Agree. Could also be for not having a mobile-friendly version, or for not using AMP.
Still, even if google does nothing illegal here and acts in good faith, do you think it’s OK to de-prioritize relevant search results based on these technicalities?
As a consumer, when I search stuff in a desktop browser, I don’t give a damn about mobile versions nor webmaster guidelines. I want search results relevant to my search query. Arbitrary limitations imposed on web masters by search engine decrease quality of results.
I do. That's actually the job of a search engine. If it wasn't choosing ranking factors, then it would just be a directory search.
Search engines are far more useful and relevant because they give more context to their results.
>when I search stuff in a desktop browser, I don’t give a damn about mobile versions
Desktop SERPs are actually different than mobile SERPs. They're crawled and indexed independently. A bad mobile site won't affect desktop results.
My mistake.
>I know technical reasons are still possible...
It could be as simple as a penalty for breaking one of their webmaster guidelines.